Abstract:

Although fluoride is an important trace element in the prevention of dental caries,
it has a narrow range between beneficial and toxic effects. Excessive fluoride intake for
example can cause dental fluorosis in infants and children whose teeth are still
developing. The primary source of this unwanted fluoride has been reported to be from
the ingestion of non-dietary sources of fluoride particularly fluoridated toothpaste.
Another potential and largely unrecognized source of unwanted fluoride can result from
ingestion of foods made with mechanically separated chicken. Mechanical separation of
chicken is a manufacturing process that results in bone particles in the final product,
which potentially contributes minerals including calcium and fluoride. Mechanically
separated chicken (MSC) is an ingredient in infant foods, toddler foods, canned meats,
and luncheon meats.
The present study examined the fluoride content of foods made with MSC to
determine the extent to which they could contribute to the total fluoride intake of infants
and children. The calcium content of these foods was also measured to determine if a
positive relationship existed between calcium and fluoride concentrations in foods
containing MSC because of the likelihood that fluoride and calcium in MSC originate
from the bones. The fluoride and calcium concentrations of the same brands of foods
made with mechanically separated turkey (MST) were also measured. In addition, both
the fluoride and calcium content of chicken bones themselves was measured.
The fluoride content of each blended sample was determined in duplicate with a
fluoride combination electrode following perchloric acid facilitated diffusion of hydrogen
fluoride. The calcium content of each blended sample was determined in duplicate by
atomic absorption spectrophotometry after samples were wet ashed with nitric acid.
Chicken sticks made with MSC had the highest fluoride concentrations followed
by infant foods, luncheon meats, and canned meats. A serving of chicken sticks
containing the highest fluoride concentration would provide nearly the recommended
daily intake for fluoride and nearly 1/2 of the upper limit of safety for a one year old
child. Foods made with MSC contained considerably more fluoride than the same brands
made with MST. Calcium concentration was significantly correlated with fluoride
concentration in infant foods, chicken sticks, canned meats, and luncheon meats which is
consistent with the hypothesis that the mechanical separation process was the source of
the extra fluoride found in foods examined. High fluoride content of chicken bones
found in this study supports this possibility. The major conclusion of the present study is
that foods made with MSC but not those made with MST contain high concentrations of
fluoride which can contribute significantly to the total fluoride intake of infants and
children. Variety in foods selected, so as to limit use of foods made with MSC, and
moderation in amount of MSC foods ingested would greatly reduce the risk of excess
fluoride intake (fluorosis) in infants and young children.